The present invention relates to the automotive arts, and more particularly to an adjusting mechanism for an automobile headlamp assembly.
Traditionally, headlamps on automobiles have been provided by separately mounted seal beam lamps which require independent adjustment utilizing adjusting screws which were accessible from the exterior of the auto only after certain trim or bezel components had been removed. Problems were often encountered, in that the adjusting screws became corroded or otherwise fouled with rust and road grime thus rendering the adjustment procedure often time consuming and difficult.
Automotive engineers have improved upon the headlamp assemblies, and are now proposing single housings which will contain both the high and low beam components in the form of replaceable bulbs, as opposed to the older seal beam type of arrangement. Also with the introduction of more aerodynamically efficient bodies headlamps have been designed to fit the body contour, rendering the older sealed beam type arrangements, with their exterior adjustments, obsolete. As such, it has been proposed to utilize an adjusting mechanism for the headlamps which is mounted interiorly of the car, and which can be easily and readily operated to adjust the vertical and horizontal position of the light beam. At least one of the prior art arrangements is in the form of a plastic housing into which a pair of bevel gear members are mounted, one gear member being affixed to an elongate screw which is coupled through other components to a headlight assemly, while the other gear is coupled to an elongate shaft that could be rotated utilizing a hand tool. The adjusting screw rotates with the associated bevel gear and is coupled to the headlamp housing so that rotation of the adjusting gear produces movement of the headlamp housing either in the horizontal or vertical direction as required.
The particular prior art design under discussion suffers from a number of basic flaws. To name but a few, the assembly is provided by a "clam shell" type of housing which is clamped about the engaged gear members. As such, the gear members are inadequately journaled and will rattle and often do not rotate or function properly. The seam or parting line in the housing permits the entry of moisture, road grime, grease and other contaminants which tend to foul the operation of the gears. Further, since the parting line of necessity defines a plane which includes the axis of either the adjusting screw or the drive member, any side load which might occur during operation of these members tends to part or separate the housing. This serves to further destroy the journaling for the gear members, and permits easy access to the interior of the housing by moisture, road grime, grease, etc.
Other headlamp adjusting mechanisms have been proposed which are rather complex and expensive. In this regard, attention is invited to U.S. Pat. Nos. 4,271,456; 4,309,740 and 4,524,407.
The present invention is an improvement of the above prior art, and provides a one-piece molded housing member that includes a gear receiving bore or bores which are disposed generally transversely to each other, while intersecting at a peripheral location to facilitate meshing of the gears. Respective chambers are closed by plural cap members in a first embodiment, and by a single cap member in a second embodiment which are sealed to the housing thereby preventing the entry of moisture and road grime into the chambers within which the gears are mounted. In addition, the housing and cap members are designed in conjunction with the gear members to provide full circumferential journaling for the gear members, which journaling will not be effected by any side loads applied to the adjusting screws or drive members during operation. In addition, the adjusting mechanism of the present invention is designed such that the gear-box or housing containing the gears may be assembled and sealed, with the drive shaft and adjusting screw components assembled at a later time. This permits the oompleted housing assemblies to be mass produced and drive shaft and adjusting screw components of varying length, as required, affixed when needed.